Preparation of liquid reaction products of diborane and diolefin hydrocarbons



March 28, 1961 E, J,

PREPARATION oF LIQUID REACTION PRODUCTS DE LORENZO ETAL OF DIBORANE AND DIOLEFIN HYDROCARBONS Filed Feb. 21, 1956 INVENTORS @GENE y. Of Kalff/2o BY fof/M l? F605 I I o.....l'

ATTORNEYS United States Patent '0 PmirAnATroN oF LIQuIDnEAcrroN PRODUCTS lloNglonANE AND DroLEFiN HvDRocAR-V Eiig'ene I. De Lorenzo, Niagara Falls, and JohnP. Faust,4

Kenmore, N.Y., assignors, by mesne assignments, to Olin. Mathieson Chemical. Corporation, av corporation of Virginia Filed Feb. 21, 1956, Ser. No. 565,753 4 claims. (omen-605.5)

This invention relates to a method for the production of liquid borohydrocarbonsmbyV reacting ldiborane-and adioleiin hydrocarbon having from 3 t0,5 carbon atoms.' The liquid borohydrocarbons produced areV useful asfuels when burned with air aspdescribed in application Serial No. 533,944, filed September 13, 1955, in the names of Earl A. Weilmuenster and Joel A. Zaslowsky;

The production. of liquid borohydrocarbonshas-rbeen previously proposed bythe reaction cof. diborane and unV saturated hydrocarbons in the gaseous phase and in acl-5y mixture with an inert diluent gas :at temperatures elevatedi by, indirect heat exchange. When such reactions aref carried out, however, it has been found thatinzadditionto-theliquid borohydrocarbons produced a considerable: amountof solids are formed, andthat these solids. tend; to clog the product recovery lines and condensers.;v Its has: now: been found that high yields of desirable liquid products and an appreciable reduction in the formationi of. solids can'v be achieved in theA reaction ofdiborane `and unsaturated hydrocarbons in admixture with axdilf nent gas by passingthe gaseousmixture into andr through a mass of molten metal maintainedwithin thereactiun-` temperature range.

Thus according to the method of this inventiongaseous diborane 'together with a gaseous diolefin hydrocarbon h aving fromh3 to t5 carbon atoms and a diluent gasisf passed into a mass of molten metal maintainedata temperaturer within theftrange ofy about 100 C. to 250C. The, dioleiin hydrocarbons employed.,F in the." process of, this invention include, for example, allene, butadiene, pentadiene and isoprene.

The term molten metals includes mercury and Woods metal and low melting metals such as tin together with various low melting alloys, especially those containing appreciable proportions of tin, for example, solders. The metal or alloy, however, must be unreactive with the diborane, the diluent gas, and the diolen hydrocarbon. Mercury is particularly preferred as the molten metal.

Diluent gases useful in this invention are hydrogen, nitrogen, and argon, or mixtures thereof.

The relative amounts of diborane and diolen hydrocarbons used in the process of this invention can be varied widely. In general, however, the molar ratio of diborane to diolefin hydrocarbon will be Within the range from 0.5 :1 to 10:1. In the case of the lower diborane to diolen hydrocarbon ratios, however, the liquid products produced are not has high in heat of combustion as those produced when mixtures relatively rich in diborane are employed.

The amounts of diluentl gas introduced into the reaction zone can also be varied widely, the amount so introduced in practice being dependent upon the amount of diluent required to eect etlicient mixing and heat transfer necessary for any particular mode of operation. In general, the gases entering the reaction system (diborane, diolen hydrocarbon and diluent gas) will be composed of from about 20 to 90 percent by volume of diluent gas.

icc c The, process of thefinvention isfillustratedfin FthvefoljYL lowing.,l examples.E

inthe-accompanying drawingui In,l the rdrawing numerals- 1 and'Z represent sources' such as, cylinders-ofz diboranefand diolein-hydrocarbon of valved line 14, owmetenlS, and valved line 16.' Also,

connectedlto line -10`is-nitrogenfsource 17 passing through bubble counter- 18-,Yline 19,and valved line 20.

Reactor 12S-contains -a mass'of mercury 21 heatedbyA afnichrome resistance-ribbon@(not.shown) coiled aroundA reactor 13:.Y The ,levelbfthe mercury inreactor `13- is. controlled by levelling bulb 22 and the temperature isA measured` by means of aniron-constantan thermocouple (not shown) inserted into thermowell 23.

Above reactor 13 is situated Allihn condenser 2|4V through which cold water circulates by means of lines 25Y and 26. Condenser 2.4 is connected to. product traps 27, 28 and 29'by Way of valved line 30. Trapr27 is maintained 1L-78 C. by a Dry-lcefbath and trapsfr2'8f" and 29 are maintained at;-197 C. by means of'liquid4v EXAMPLE I Diborane and=allene cylinders are permitted to come to room temperature and weighed. The diborane: cyl-'S Y inder weighsi489.07 g." and the allene cylinder 492143g:

They are placedin Dry-IceI bath 3 and Water-ice bath'4 respectively landconnectedlto itheiry respectivel flowl meters` n y 6 and 15. The entire apparatus including connecting lines to the cylinder needle valves and to the hydrogen flow meter is evacuated, The Dry-Ice land liquid nitrogen cooled baths are then placed around product traps 27,

Z8 and 29 in proper order. The apparatus is filled kwith n hydrogen at atmospheric pressure from hydrogen source` S. The mercury level in reactor 13 is adjusted by means of levelling bulb 22 to a position 2" above the top of` inlet tube 12. Hydrogen is admitted from hydrogen source 8 at a rate of 85 cc./min. and heating is started. With the mercury at a temperature of 166 C., diborane and allene are admitted to provide a molar feed ratio corresponding to H2zB2H6zC3H8 of 5.7:1.9:1.

The diborane is intimately mixed with hydrogen inV mixing tube 7 prior to being mixed with the allene.

Further mixing of the reactant streams is provided by glass frit 11 situated in the inlet tube 12 to the reactor 13. This disc also acts as a ame arrester iny preventing the backward propagation of the reaction. The reactant gases bubble through the mercury and are cooled in Allihn condenser 24 to prevent polymerization. Nonvolatile, liquid products collect on the mercury surface .A

and the volatile products together with unreacted di-` borane and allene are condensed in traps 27, 28 and 29.

Most of the allene-diborane product condenses in thejk 78 C. trap with a small amount collecting in the'rst 197 C. trap. Most of the unreacted diborane condenses in the first 197 C. trap and the remainder in patented? Mar-v. 2281i *y the second 197 C. trap. Non-condensable gases are vented through a fritted disc immersed in mineral oil by means of line 31.

At the completion of the run, i.e., after 42 minutes the diborane and allene flows are stopped, heating is discontinued and the system is ushed with hydrogen for approximately minutes. The mercury level is lowered below the inlet tube and the entire system is evacuated. The cylinders are removed, allowed to warm up, and reweighed to obtain the weight of reactant gases used. The diborane cylinder weighs 486.88 g. indicating that 2.19 g. of diborane was used and the aliene cylinder weighs 490.77 indicating that 1.66 g. of allene Awas used. Volatile products are transferred to the high vacuum line where they are fractionated through three traps maintained at 78 C., 130 C. and 197 C. respectively.

Any remaining products are then ushed from the apparatus by means of nitrogen from source 17 introduced by means of lines 19 and 20.

The chief product is 1.13 g. of a colorless liquid containing 34.1 percent boron which collects in the 78 C. trap along with a few entrained solids. A small amount of non-volatile liquid and solids remains on the mercury surface and on standing forms a hard paste with the mercury droplets.

The following Table I sets forth the pertinent data with respect to additional runs wherein diborane is reacted with allene.

EXAMPLE II Diborane and butadiene cylinders are permitted to come to room temperature and weighed. The diborane cylinder weighs 487.30 g. and the butadiene cylinder 512.42 g. The procedure of Example I is followed except that the hydrogen flow rate is set at 79 cc./min. at S.T.P., the mercury is heated to 150 C. prior to the start of the run, and the diborane and butadiene ows are adjusted to provide a molar feed ratio corresponding to HzzC4HzB2H5 of 4.51:1.75:1. The reaction of butadiene with diborane proceeds smoothly to yield about 2 g. of a viscous non-volatile yellow orange liquid containing 16.3 weight percent boron which collects on the mercury surface. A small amount of a volatile product is formed which dissolves the Apiezon T grease in Vthe vacuum line and has not been characterized.

The following Table II sets forth the pertinent data with respect to additional runs wherein diborane is reacted with butadiene.

Table I Molar Feed Mercury Average Amount Percent Flow Rate, H2* Ratio, Height. Temperol Prod- Boron ln Hg/ B211!! inches ature, uct, g Product 3H; degrees *Ce/min. at S.T.P.

Table Il Molar Feed Mercury Reaction Amount Percent Flow Rate, H1* Ratio, Height, Tcmper of Prod- Boron ln HzzCiHi: inches aturv, uct, g. Product BzHa degrees (approx.)

We claim:

1. A method for the production of liquid reaction products of diborane and a diolefin hydrocarbon which comprises passing gaseous diborane, a gaseous diolein hydrocarbon having from 3 to 5 carbon atoms, and an inert diluent gas into a mass of a molten metal inert with respect to the reactant gases maintained at a temperature within the range from about C. to 250 C. and recovering liquid organoboron products from the gaseous efuent.

2. The method of claim 1 in which the molten metal is mercury.

3. The method of claim 2 in which the dolefin hydrocarbon is allene.

4. The method of claim 2 in which the diolefin hydrocarbon is butadiene.

References Cited in the le of this patent Gregory: Uses and Applications of Chemicals and Related Materials, vol. I, Reinhold Pub. Corp., New York, 1939, page 371. (Copy in Div. 46.)

Whatley et al.: American Chemical Society Journal, vol. 76 (1954), pages 835 to 838. (Copy in Sci. Lib.) 

1. A METHOD FOR THE PRODUCTION OF LIQUID REACTION PRODUCTS OF DIBORANE AND A DIOLEFIN HYDROCARBON WHICH COMPRISES PASSING GASEOUS DIBORANE, A GASEOUS DIOLEFIN HYDROCARBON HAVING FROM 3 TO 5 CARBON ATOMS, AND AN INERT DILUENT GAS INTO A MASS OF A MOLTEN METAL INERT WITH RESPECT TO THE REACTANT GASES MAINTAINED AT A TEMPERATURE WITHIN THE RANGE FROM ABOUT 100*C. TO 250*C. AND RECOVERING LIQUID ORGANOBORON PRODUCTS FROM THE GASEOUS EFFLUENT. 